FH is caused by inheriting one of three faulty genes from a parent. One in every 250 people in the UK may be affected. Cholesterol levels are usually between 7.5 and 12 mmol/l but sometimes they can exceed 20 mmol/l. High cholesterol is present from birth onwards. If untreated, people with FH can die from a heart attack before the age of 50. It is normally treated with a high potency statin and a healthy lifestyle. Most people with FH inherit one faulty gene from one parent, but one in 250,000 is believed to inherit two faulty genes; one from each parent. Known as homozygous or combined heterozygous FH this is usually treated using LDL apheresis.

People with FCH typically have raised cholesterol and triglycerides. It affects about 1% (1 in every 100) people. The way in which it is inherited is not as well understood as FH but it also linked with premature heart disease. Usually cholesterol and triglyceride levels only rise in adults, and usually cholesterol levels are not as high as in FH. Treatment includes a healthy diet and lifestyle and medication.

Polygenic high cholesterol

This is relatively common and probably affects about half of all people with raised cholesterol living in the UK. It is caused by the small effects of many genes which altogether raise the cholesterol level.

This has several names including dysbetalipoproteinaemia or remnant hyperlipidaemia. It is fairly uncommon affecting about 1 in 5000. Typically both cholesterol and triglycerides are raised. If untreated it can result in early heart disease. It is usually treated with fibrates and statins.

Also known as Cholesterol Storage Disorder, Wolman’s Disease or LAL deficiency it typically results in raised cholesterol and triglycerides. It is relatively rare – affecting about 25 people per million.